GLO1456W Directory increase requires exclusive control, but data set is shared by one or more other tasks (2).

Explanation
 During the dynamic PDS directory increase function, Advanced Allocation Management  required
exclusive control of the data set to maintain the integrity of the
PDS directory, but was unable to obtain it. Recovery cannot continue. 

User response If you still want the directory increase, stop any
processes that have shared ownership of the data set and run the process
again.